Generally, the field of energetic materials uses compounds composed of carbon, hydrogen, nitrogen, and oxygen. These are typically arranged to form explosophoric functionality such as N-nitro, C-nitro, O-nitro, and azido.
Energetic materials containing the geminal dinitro groups (—C(NO2)2, gem-dinitro) have generally low sensitivity to unplanned stimuli, making them particularly valuable in the creation of munitions meeting Insensitive Munition (“IM”) requirements. Additionally, these explosophores are attractive due to their high oxygen content and high energy.
A number of gem-dinitro containing compounds have found application in the production of energetic materials. Typically, these gem-dinitro containing materials are prepared by conversion from a mononitroderivative with an active hydrogen using the silver nitrate method or the potassium ferricyanide method. Alternatively, they may be prepared by functional group manipulation of an existing gem-dinitro containing compound.
Geminal dinitro alcohols such as 2,2-dinitropropanol, 2,2,-dinitrobutanol, and fluorodinitroethanol have the versatility to allow the preparation of a range of energetic plasticizers, binders and oxidizers. For example, 2,2-dinitropropanol is useful in the production of the energetic plasticizers bis(2,2-dinitropropyl formal) (“BDNPF”) and bis(2,2-dinitropropylacetal) (“BDNPA”).
Although azide groups do not contribute to the oxygen balance of the compounds in which the azide group is contained, organic azides can make an exceptional contribution to the heat of formation (75-95 kcal/mol) and the total energy released upon decomposition. Compounds containing both an azide and gem-dinitro group can possess higher energy than the corresponding azido (N3−) compounds and thermal stability.
Displacement of leaving groups adjacent to gem-dinitro moieties is known to be difficult due to inductive effects. Previous attempts to create 3-azido 2,2-dinitropropyl chloride by displacement of 1,3 dichloro 2,2-dinitropropane have been unsuccessful for at least this reason. The general approach of preparing 1,2 and 1,3 azido alcohols by displacement of an intermediate cyclic sulfate is well known in organic chemistry.